Science and Health

Flu shot in pregnancy benefits baby

Updated: 2009-11-02 13:54

LOS ANGELES: Pregnant women who get flu shots will have bigger and healthier babies, studies show.

Flu shot in pregnancy will also help prevent preterm births and reduce rates of hospitalization for newborns, according to the studies presented at this week's annual meeting of the Infectious Disease Society of America in Philadelphia.

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In flu pandemics, pregnant women were at risk for giving birth prematurely to underweight babies, the studies warned.

In one study, researchers at Emory University's Rollins School of Public Health analyzed data on 6,410 births in Georgia and found that the risks of premature delivery and having a low birth-weight infant were significantly reduced among the 15 percent of women who received a flu shot during pregnancy.

During the height of the flu season premature births among vaccinated women fell 70 percent, compared with unvaccinated women, said Dr. Saad B. Omer, an assistant professor of global health and epidemiology at the school.

And the likelihood of having a small baby was reduced 70 percent, Omer said in a news release.

In another study, Yale University School of Medicine researchers found that the mother's flu shot during pregnancy was 78.9 percent effective in preventing her non-vaccinated infant from being hospitalized during the first year of life and 85.3 percent effective in preventing hospitalization from infancy to 6 months.

Women who were vaccinated were 30 percent less likely to develop respiratory illness with fever, and those women had substantially heavier infants than unvaccinated women, said researchers at Cincinnati Children's Hospital Medical Center.

Flu among infants whose mothers were vaccinated was reduced 63 percent, according to the researchers who looked at the relationship between flu shots and birth weight in Bangladesh.

In yet another study of pregnant women in Bangladesh, Emily Henkle, from the Bloomberg School of Public Health at Johns Hopkins University in Baltimore, wanted to determine the rate of flu infection in their infants.

Henkle found high rates of flu among infants younger than 6 months whose mothers had not been vaccinated.

Despite the benefits of seasonal flu vaccine, the rate of vaccination among pregnant women is "dismal" because only about 25 percent of American pregnant women are getting vaccinated, according to figures released at the just-concluded meeting.